The invention relates to the general field of the detection, notably the radar detection, of mobile or fixed targets. It deals more particularly with the problem of the detection of small targets moving around in a noise-affected environment.
With respect to the radar detection of small targets in an electromagnetic environment disturbed by clutter, sea clutter for example, one of the main problems to be solved to optimize the detection (and consequently the radar-tracking) of the targets consists in finding a means for reducing the false alarm rate by suitably separating the signals corresponding to targets from the signals constituting the ambient clutter, the fluctuation of the signal corresponding to the clutter generating, in a known manner, false alarms. To solve this problem, it is generally necessary to extract from the received signal the greatest possible quantity of information. Now, the simple analysis of the signals received on an antenna revolution often does not make it possible to clearly distinguish whether the received signal corresponds to the signal reflected by a small target or whether this signal corresponds to a particular manifestation of the clutter, the signal produced by a breaking wave for example. It is consequently sometimes necessary to use the information received from one antenna revolution to another in order to be able to make the distinction.
Consequently, the information that is deemed significant that is extracted from the signals received from revolution to revolution must be correlated by taking into account the fact that from one antenna revolution to another the signal reflected by a real target undergoes variations associated with the kinematics of that target. It is therefore necessary to apply a temporal kinematic filtering, in three dimensions, to the received signal, bearing in mind that a target is likely to move in the three dimensions of space. The expression “significant information” should be understood here to mean any information extracted from a signal that has satisfied the detection criteria.